iio: exynos_adc: do a soft reset in case of timeout

Do a soft reset software if a timeout happens.
This is applicable only for ADC_V2.

Signed-off-by: Naveen Krishna Chatradhi <ch.naveen@samsung.com>
Reviewed-by: Doug Anderson <dianders@chromium.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

diff --git a/drivers/iio/adc/exynos_adc.c b/drivers/iio/adc/exynos_adc.c
index a1f6d90..a9946ec 100644 (file)
--- a/drivers/iio/adc/exynos_adc.c
+++ b/drivers/iio/adc/exynos_adc.c
@@ -112,6 +112,30 @@ static inline unsigned int exynos_adc_get_version(struct platform_device *pdev)
        return (unsigned int)match->data;
 }
 
+static void exynos_adc_hw_init(struct exynos_adc *info)
+{
+       u32 con1, con2;
+
+       if (info->version == ADC_V2) {
+               con1 = ADC_V2_CON1_SOFT_RESET;
+               writel(con1, ADC_V2_CON1(info->regs));
+
+               con2 = ADC_V2_CON2_OSEL | ADC_V2_CON2_ESEL |
+                       ADC_V2_CON2_HIGHF | ADC_V2_CON2_C_TIME(0);
+               writel(con2, ADC_V2_CON2(info->regs));
+
+               /* Enable interrupts */
+               writel(1, ADC_V2_INT_EN(info->regs));
+       } else {
+               /* set default prescaler values and Enable prescaler */
+               con1 =  ADC_V1_CON_PRSCLV(49) | ADC_V1_CON_PRSCEN;
+
+               /* Enable 12-bit ADC resolution */
+               con1 |= ADC_V1_CON_RES;
+               writel(con1, ADC_V1_CON(info->regs));
+       }
+}
+
 static int exynos_read_raw(struct iio_dev *indio_dev,
                                struct iio_chan_spec const *chan,
                                int *val,
@@ -149,6 +173,8 @@ static int exynos_read_raw(struct iio_dev *indio_dev,
        timeout = wait_for_completion_timeout
                        (&info->completion, EXYNOS_ADC_TIMEOUT);
        if (timeout == 0) {
+               dev_warn(&indio_dev->dev, "Conversion timed out! Resetting\n");
+               exynos_adc_hw_init(info);
                ret = -ETIMEDOUT;
        } else {
                *val = info->value;
@@ -230,30 +256,6 @@ static int exynos_adc_remove_devices(struct device *dev, void *c)
        return 0;
 }
 
-static void exynos_adc_hw_init(struct exynos_adc *info)
-{
-       u32 con1, con2;
-
-       if (info->version == ADC_V2) {
-               con1 = ADC_V2_CON1_SOFT_RESET;
-               writel(con1, ADC_V2_CON1(info->regs));
-
-               con2 = ADC_V2_CON2_OSEL | ADC_V2_CON2_ESEL |
-                       ADC_V2_CON2_HIGHF | ADC_V2_CON2_C_TIME(0);
-               writel(con2, ADC_V2_CON2(info->regs));
-
-               /* Enable interrupts */
-               writel(1, ADC_V2_INT_EN(info->regs));
-       } else {
-               /* set default prescaler values and Enable prescaler */
-               con1 =  ADC_V1_CON_PRSCLV(49) | ADC_V1_CON_PRSCEN;
-
-               /* Enable 12-bit ADC resolution */
-               con1 |= ADC_V1_CON_RES;
-               writel(con1, ADC_V1_CON(info->regs));
-       }
-}
-
 static int exynos_adc_probe(struct platform_device *pdev)
 {
        struct exynos_adc *info = NULL;